The author repeats the formula earlier used in Haggai 1:1, the word of the Lord came by the hand of Haggai.
The prophet does so in order to emphasize the contrast between the excuse of the people (Haggai 1:2) and the Lord’s question that follows (Haggai 1:4).1 Furthermore, the repetition may signal that the prophet is moving his attention from the leadership, Zerubbabel and Joshua, to the people.2
3 Then the word of the LORD came by the hand of Haggai the prophet,